TOMATO PRODUCTION: Facing the challenges and recognizing the opportunities

Tomato production has come across many challenges over the last few years. Even with many years of experience in tomato production and development, the tomato producer is often faced with questions for which the answer is not clear or in a textbook.

Johan Stronkhorst SAKATA

The main challenges that producers have experienced are usually caused by diseases like tomato curly stunt virus, fusarium wilt race 3, bacterial wilt and the most recent tuta absoluta, which is almost the final nail in the coffin. The use of resistance in new varieties has helped to address some of these issues, and techniques like grafting made it possible for producers to sustain production.

If what is happening on a global level would be applied in South Africa, the trend to produce tomatoes in protected culture will be the future – producers need to limit the exposure of tomato plants to pathogens and minimise the impact of environmental conditions.

Tomatoes are still considered to be one of the three biggest vegetables consumed in South Africa. Their versatility creates a high demand for fruit in all seasons, being consumed in salads, soup or stews. Indeterminate salad or round fresh market tomatoes remains the most popular segment for tomatoes with the Saladette market growing in popularity. The salad and Saladette markets are commodity markets with various channels of marketing that can range from on-farm sales, fresh produce markets and retail.

Pricing is very much affected by supply and demand and can be very profitable, however, producers sometimes struggle to sell their produce for profit. It is for this reason that optimal yields should be achieved to ensure profitability. To make a basic calculation: if the producer can harvest a single fruit more per plant on an average plant population, he can add two-tonne tomatoes to the yield.

For growers wanting to expand to new segments, the op- portunity would be to consider the speciality market. In general, these tomatoes are produced in smaller volumes at higher retail prices direct to retail groups. The speciality tomato market has seen many developments in recent years and the popularity of these tomatoes is growing, with more exposure being given to new recipes and cooking ideas. South African consumers are now more than ever aware of world trends. Characteristics that are required are variable unique colour, taste, size and shape.

There are various new speciality tomato varieties available on the market which brings new and exciting market opportunities into the segment. To be successful in the production of this segment, the secret lies in the full development of the different flavours that can be experienced. The consumer will not buy a new “type” of tomato if the taste experience is not pleasant. For this reason, it is critical that producers aim to achieve the best flavour in these tomatoes and this is not only a measure of the sugar content (brix percentage). There are many factors involved in the development of flavour in tomatoes and the management by the producer plays a key role in this. The balance between flavour development and the economic viability of a variety is also a fine line that needs to be managed.

The amount of nutrients applied and the ratio between the elements are critical for the different growth stages of the tomato plant. One of the biggest contributors is water, not only the amount of water but also the time of irrigation, when the first and last irrigation cycle per day is done and if it may differ during the change of season or climatic conditions. This depends very much on the type of medium being used and no single recipe is available. Most producers that supply retailers of tomatoes have already done a lot of work on irrigation themselves and with the assistance of seed companies and consultants, the requirement for each variety is fine-tuned.

Other factors that can have an influence on flavour development are temperature, light intensity and relative humidity. These factors need to be managed according to specific local conditions. These factors have an optimum range in which the development of flavour is at its best. If one of these factors falls outside the optimum range, the flavour of the fruit can be negatively affected.

Light intensity plays a huge role in flavour as it is the basic driver of photosynthesis and despite this, light intensity is often overlooked. If the light intensity is too high or too low, it can affect the flavour negatively. Not only the amount of light is critical, but the quality and wavelengths also need to be measured and recorded. It is therefore important for the tomato producer to look at local conditions and make informed decisions when it comes to adjusting and following someone else’s advice.

Finally, one must never forget the amount or concentration of carbon dioxide in the greenhouse, especially in cooler conditions when producers try to conserve heat at the expense of carbon dioxide. This can lead to a sharp decline in the rate of photosynthesis, leading to the loss of growth and other developmental processes.

Indeterminate speciality varieties are still mostly grown unTO PAGE 12

Tomato production: Facing the challenges and recognizing the opportunities | FROM PAGE 11 der protection in plastic tunnels which is justified by the added value of these products. Before entering this market segment, it is very important that the tomato producer does intensive research in terms of marketing and pricing structures before planting these tomatoes.

Chocostar* is a vigorous, indeterminate brown­coloured mini plum tomato variety especially suited for production under protection.

Varieties

Sakata has an extensive range of speciality tomato varieties available in their tomato seed range that covers a variety of colours and shapes.

Tinker is an indeterminate plum-shaped variety suited for production under protection and open field. The yield potential is excellent and bears approximately 40 fruits per cluster when double-stem pruning is practised. The fruit has an excellent flavour with approximately 7% to 10% sugar content. The fruit is brilliant red, tough against cracking and weighs about 12 to 18 g. Tinker can be produced in the open field and is thus exposed to environmental conditions, both climatic and disease. Tinker is currently still the leading variety in South Africa for baby plum shape types and has shown very good adaptability, quality and yield. It is difficult to find new varieties that fulfil all the requirements in one variety as Tinker has done over the past few years. It therefore remains the best plum-shaped variety on the market.

Lucystar* is a vigorous, indeterminate mini plum tomato variety especially suited for production under protection. The yield potential is very good with good adaptability. It is the preferred choice of leading retail stores due to the excellent flavour, high sugar content and bright yellow fruit colour that does not turn orange in high light conditions. Fruit is unlikely to crack and weigh approximately 15 g with a very good shelf life.

Amai* is a vigorous, indeterminate baby plum tomato variety especially suited for production under protection but can be grown outside. It does have a slightly larger fruit size than Tinker and is more oval in shape.

Robin* is a vigorous, indeterminate cherry tomato variety for production under protection. The yield potential is very good with good adaptability. It is preferred due to the excellent flavour, high sugar content and bright red fruit colour. Robin’s* fruit is unlikely to crack and weighs approximately 15 - 18 g with a very good shelf life.

Chocostar* is a vigorous, indeterminate brown-coloured mini plum tomato variety especially suited for production under protection. It has a unique flavour profile.

Rozestar* is a vigorous, indeterminate pink mini plum tomato variety especially suited for production under protection. It has a very sweet taste and uniform fruit size. Harvesting is critical with this variety to achieve the best results between flavour and shelf life.

Kinkanstar* is an indeterminate orange mini plum tomato variety. It’s fruit is very uniform and weighs approximately 1520 g with a very good shelf life and taste.

The combination of Robin*, Chocostar*, Kinkanstar* and Rozestar* on a multi-punnet pack is sure to give the consumer a fantastic taste experience full of different flavour and colour.

Contact the Sakata representative for more information on Sakata’s extensive tomato range, or visit the website at www.sakata.co.za.

*Experimental: This variety does not appear on the current South African Variety list, but has been submitted for registration.

DISCLAIMER: This information is based on Sakata’s observations and/ or information from other sources. As crop performance depends on the interaction between the genetic potential of the seed, its physiological characteristics and the environment, including management, Sakata give no warranty express or implied, for the performance of crops relative to the information given nor do Sakata accept any liability for any loss, direct or consequential, that may arise from whatsoever cause. Please read the Sakata Seed Southern Africa (Pty) Ltd Conditions of Sale before ordering seed.